De Novo Asymmetric Syntheses of SL0101 and Its Analogues via a Palladium-Catalyzed Glycosylation
作者:Mingde Shan、George A. O'Doherty
DOI:10.1021/ol062076r
日期:2006.10.1
upon a diastereoselective palladium-catalyzed glycosylation, ketone reduction, and dihydroxylation to introduce the rhamno-stereochemistry. The asymmetry of the sugar moiety of these kaempferol glycosides was derived from Noyori reduction of an acylfuran. An acetyl group shift from an axial (C-2) to equatorial position (C-3) under basic conditions was also described. [reaction: see text]
天然山ka酚糖苷SL0101(1a)及其类似物1b-e及其对映异构体的对映选择性合成已通过7-10个步骤完成。这些途径依赖于非对映选择性钯催化的糖基化,酮还原和二羟基化以引入鼠李糖立体化学。这些山emp酚糖苷的糖部分的不对称性源自酰基呋喃的Noyori还原。还描述了在基本条件下乙酰基从轴向(C-2)转移到赤道位置(C-3)。[反应:看文字]